1. Field of the Invention
This invention relates to devices for restraining the rotation of wheels, and especially to such devices for restraining the rotation of wheels on shopping carts to prevent the carts from freely rolling down inclines.
2. Description of the Related Art
Most visitors to grocery stores and shopping centers have witnessed a shopping cart rolling down an incline in a parking lot. These runaway carts are likely to ram parked or moving cars, causing property damage which results in clams against owners of the carts.
Several attempts have been made to provide some mechanism which will prevent carts from rolling down a gentle incline such as may be found in a paring lot. Of course, any such device must also allow the cart to be used in its normal manner. High cost, maintenance, and difficulty of use have limited the success of efforts to solve this problem.
Much of the prior art discloses user-operated bring devices which require activation by a user, either to engage the brake to prevent the cart from rolling or to disengage the brake so the car can be moved. An example is seen in Rutter et al., U.S. Pat. No. 5,328,000. Other devices continuously apply friction to one or more wheels; this latter type of device generally has means for adjusting the amount of applied friction, increasing the complexity and number of parts required. An example of the latter type is Hicks, U.S. Pat. No. 5,275,472.